Electric switch



Aug 25, l936'- H. J. HAMMERLYY 2,051,943

ELECTRIC SWITCH Filed March 4, 1936 INVENTOR 10 HERrgYAN J. HAMMERLY,

Patented ug. 25, A 139364 UNITED STATES ELECTRIC Herman J. Hammerly,

signor to ing Company, Plainvill of Connecticut Application March 4, 1

16 Claims.

. My invention relates particularly to double pole Aswitches of the type intended to be normally actuated manually but which will automatically'operate the switch' to open the circuit in case of an overload in either pole of the circuit.

IThe main object .is to provide a double pole .switch of this character which can be readily .operated manually but which is sensitive and operably responsive to overload conditions in either pole of the circuit. The manual operation .is preferably eifected by-means of an oscillating lever or toggle action. Thermostatic means is provided to open the circuit automatically in case of an overload. For this purpose a latch is provided which is adapted to hold the parts of the switch in the operable position under normal circumstances and this latch is subject to thermostatic action to release the switch in case of an -overload in eitheror both poles of the circuit.

I have shown herein the invention as applied to a switch and mechanism of the type of my Patent Number 2,038,105 dated April 21, 1936.

Fig. 1 shows a iront view of. s'uch a construction.

Fig. 2 is a section and side view with the parts of the switch in the open circuit or oil? position.

Fig. 3 is a rear View of the switch.

Fig. 4 is an end view looking upwardly at the mechanism as shown in Fig. 1.

Fig. 5 is a sectional view in side elevation with parts of the mechanism in the closed circuit position.

Fig. 6 is a perspective view of two members of the latch and actuating mechanism.

Y The parts of the switch are mounted upon and enclosed within two insulating members, namely a base 8 to which the parts of the mechanism are directly secured and the back or cap member 9. A strap I extends across the face and serves as a means for supporting the switch within the usual wall box. The insulating parts are secured together and to the strap by means of screws II.

The circuit terminals I2, i3, I4 and I5 are suitably arranged and preferably accessible at the front. Stationary contacts I6 and I1 are secured to the insulating member 8. The movable switch arm I8 is resilient and has one end anchored to the base by an eyelet I9 and the other end is adapted to engage the contact I6. The brackets 2li and 2| are secured to the rear of the insulating member 8 and are connected by al resistance heatery wire 22. The bracket 20 has one end connected tothe terminal I3 and the bracket 2I has one end in electric engagement with the stationary end of. the switch arm I8 so-that one pole of the circuit through the switch when the circuit SWITCH New Britain, conn., u- The Trumbull Electric Manufacture, Comi., a corporation 936, Serial No. 66,994

(Cl. 20o-116) is closed extends from terminal I 2 to the stationary contact I6, thence through the switch arm I8 to the bracket 2|, the heater 22, the bracket 20 to the terminal I3.

At the othei` side of the switch the spring `v switch arm 23 has one end anchored to the eyelet 24 and the other end adapted to engage the stationary contact I'I. The bracket 25 has one end secured to the base by the terminal I5. The bracket 26 has one end secured to the base by lo the eyelet 24. A resistance heater wire 2'I electrically connects the rear ends oi the brackets 25 and 26. An insulating cross bar 28 connects the two arms I8 and 23. A mica shield 30 is supported by the rear ends of the brackets 20, 2l, 25 15 and 26 and is interposed mechanically between the resistance heater wires 22 and 21 and the switch mechanism. An additional support 3i for the mica shield may be provided and which also serves as a convenient means for identifying the calibrated capacity .of the detachable and replaceable heater unit.

The switch actuating mechanism is carried by the strap or face plate I0 which for that purpose is provided with side flanges 32. The finger lever 33 is provided with a yoke 34 whose side arms are pivoted between the flanges 32.

The carrier plate 35 (shown in Fig. 6) is also pivotally mounted between the flanges 32 and provided with lugs 35' which project into slots 30 in the flanges 32 to limit the swinging movement of the carrier plate. A push rod 36 is loosely mounted in the base of the yoke 34 and has its rear end hinged to the front end of the carrier plate 35;

A spring 31 on this rod 36 serves to exert pressure to hold the parts in the on or off position as the case may be. A dog or catch member 38 is pivotally carried by ears on the carrier 35 and has two arms 39 and 40. The arm 39 is adapted 40 to engage the cross bar 28 for moving the switch arms I8 and 23 to close the circuit. The other arm 40 is adapted to engagea bimetallic thermostatic latch member 4I which is supported by the post 42 which in turn is secured to the base 8 45 by a screw 43. Cross piece 44 serves as a stop or abutment for thearm 39 when the latch member 4I has been heated by an overload andreleases the arm 4U of the dog 38.

'I'he manual operation of the switch under nor- 50 mal load conditions is the samegas that of the conventional type of toggle switch. When the parts oi' the switch are in the position shown in Fig. 2 the circuit is closed by simply lifting the :linger piece 33 whereupon the spring and toggle 55 mechanism closes the circuit with a snap action. When the circuit is closed and the parts are as shown in the position of Fig. 5, the switch is opened by simply pulling down on the lever 33 whereupon the toggle mechanism opens the circuit with a snap action.

In case the circuit is closed and an overload occurs in either pole of the circuit, one or both of the resistance wires 22 or 21 is heated and as a consequence the thermostatic latch member 4I is warped and the arm 40 of the dog 38 is released so that the pressure ofthe spring arms I8 and 23 tilts the dog and both poles of the circuit are opened. To re-set the switch it is merely necessary to tilt the nger piece 33 downward from the position shown in Fig. 5 to the position of Fig. 2 which throws the catch back into the position shown in Fig. 2.

It will be seen from the foregoing that the switch may be actuated manually under normal circumstances vin a manner customary to toggle action switches. When an overload occurs one or both of the resistance wires 22 and 2l are heated hand the thermostatic latch 4| is warped so as to releasev the switch and open the circuit. By providing la resistance heater in each pole of the circuit the switch is made much more sensitive and reliable and less likely to be injured by an overload than is the case when a resistance heater is employed in one side only of the circuit.

AIt will be seen that the normal toggle action is wholly independent of the thermostatic action. The resistance heater units are detachable and can be readily replaced.

It will also be obvious that the same mechanism may be employed for diierent capacities by the simple expedient of properlydesigning the thermostatic latch and calibrating the heater units. It will be also noted that the only springs required in the switch are the toggle spring 31 and the switch arms I6 and 23.

One prime advantage is the fact that but a I single thermostatic element is used, which may be actuated by either of the two resistance heaters. This eliminates costly duplication of tripping mechanisms and conserves space.

I claim:

1. A double pole snap switch having a single thermostatic latch and a resistance heater in each pole of the circuit, each heater coacting with the latch to open the circuit upon an overload in the circuit.

2. A double pole switch havingquick break mechanism, and thermostatically actuated means for opening the circuit in case of an overload in the circuit, said means including a resistance heater connected in series with each pole of the circuit.

3. A double pole switch having quick break mechanism, a iinger piece for normally actuating the switch to open and close the circuit, a single thermostatic latch normally restraining the quick break mechanism and a heaterin each pole of the circuit for coacting with the latch to release the said latch and permit the quick break mechanism to operate to open the circuit in case or an overload in the circuit.

4. A double pole snap switch having actuating means, latch mechanism normally coacting with the actuating means so that the circuits through both poles of the switch may normally be opened and closed manually and including a single thermostatic latching member for holding'the circuit closed, and a resistance heater in each pole of the circuit positioned to' individually or simultaneously .affect said thermostatic member and release the latch mechanism and open the circuit in case of an overload in the circuit.

5. A double pole electric switch including a quick break mechanism, means including a nger piece for normally actuating the switch to open and close the circuit, a single latch normally restraining the quick break mechanism and means including a heater in each pole of the circuit for coacting with the latch to release the said latch and permit the quick break mechanism to operate to open the circuit in case of an overload in the circuit.

6. A double pole electric switch having two pairs parts of the switch in manually operable relation,

and means in each pole of the switch positioned to separately or simultaneously affect said thermostatic member and release the latch mechanism and open the circuit in case of an overload through either pair of contacts.

7. An electric switch having quick break mechanism including two stationary contacts and two movable switch members coacting therewith, and thermostatically actuated means for releasing the movable switch members and opening the circuit in case of an overload, said means including a resistance connected in series with each stationary contact.v

8. An electric switch having two pairs of contacts, a thermostatic latch for holding the parts in a closed circuit position and a heater in circuit with each pair of contacts, each heater coacting with the latch to open the circuit upon an overload in the circuit.

9. In a thermostatic switch, two pairs of contacts, manual means for making and breaking the circuit through lsaid contacts including a pivoted catch, a thermostatic latch coacting with said catch and an independently replaceable heater unit in series with each pair of contacts, either or both of said units being adapted to operably aiect said latch.

10. In a toggle actuated thermostatic switch,

twolpairs of contacts, a toggle action device, a pivoted catch adapted to be actuated by said device, a thermostatic latch for holding the parts in a closed circuit position and an independently replaceable heater unit in series with each pair of contacts, either or both of said units being ,adapted to operatively affect said latch.

11. An electric switch including two sets of` contacts, a pivoted operating lever, a pivoted toggle member hinged to the operating lever, a catch member hinged to the toggle member, a spring pressed switch member coacting with the catch member, a. thermostatic latch member normally interposed in the path of the catch member and an independently replaceable heater unit in series with each set of contacts, either or both of said units being adapted to operatively aiect said latch member.

12. A snap switch including two pairs of stationary and movable contacts, the movable contacts being normally biased to the o position, operating mechanism coacting with the movable contacts and including a nger lever, an oscillating member connected to the iinger lever, means pivotally carried by the oscillating member and free to move on occasion of an overload in the circuit, a thermal element holding said means under normal circuit conditions, a heater unit in series with each pair of contacts, either or both of said units being adapted to operably affect said thermal'ele'ment and a throwing spring coacting with the oscillating member for actuating the. same and the said means carried thereby so as to open and close the circuits with a snap-action when said finger lever is manually operated and so as to open the circuits with a snap action when the thermal element releases said means.

13. In a snap switch, an insulating support having a passage extending from front to rear of said support, a stationarycontact and a cooperating movable contact carried on each side of said support, each of said movable contacts being biased to an open circuit position, a thermally actuated element carried by the support, a heater unit in series with each set of contacts, either or both of said heater units being adapted to operably affect said thermal element, a frame secured to said support and having flanges projecting into said passage, 'a nger lever pivotally carried by said flanges, an oscillating member pivotally carried by and restricted in its movement by said flanges, a latching member pivotally carried by said oscillating member and free to move on occurrence of an overload in the circuit, one end of said latching member being held by said thermally actuated element under normal circuit conditions and adapted to be released by the action of the thermally actuated element upon an overload condition in the circuit, the other end of said latching member coacting with the movable contacts so that the movable contacts may be moved by the action of the finger lever to' open and close the circuit.

14. In an electric switch having two pairs of contacts including manually operable actuating mechanism, a single bimetallic thermostatic latch for holding the parts in a closed circuit position* and a resistance heater in circuit with each pair of contacts for actuating said latch to release the parts and open the circuit.

15. A doublepole snap switch having a single bimetallic thermostatic latch and a. resistance` HERMAN J. Hazan/manifY 

